This invention relates to an antenna provided to a vehicle rear window glass for receiving FM radio and television (TV) broadcast waves. The antenna is constructed of conductive strips attached to the window glass by using a space above defogging heater strips. The antenna is particularly suited to automobiles.
In the automobile industry recently attention has been paid to a so-called window glass antenna for receiving broadcast waves, and recently there is an increasing demand for a window glass antenna which can efficiently receive both FM radio broadcast waves and TV broadcast waves. To meet such a demand there are several proposals.
For example, JP 61-203702 A proposes a windshield antenna having, as an essential element, a linear element which extends vertically in the central region of the windshield, and JP 61-121603 A proposes a rear window glass antenna which is arranged in a space left above a set of defogging heater strips and includes two feed points which are connected to two different points of an antenna element, respectively.
However, generally it is unfavorable for the driver's field of view to provide an antenna in a central region of the windshield.
In the case of providing an antenna to an automobile rear window glass which needs to be provided with defogging heater strips, the antenna must be arranged in a relatively narrow space contiguous to an edge of the window glass since a central region is occupied by the heater strips. Since the allowed space is narrow and off-centered it is difficult to construct an antenna which exhibits high reception gain over a wide range of frequency including the FM radio broadcasting bands and both the VHF and UHF bands for TV broadcasting, and the difficulty still remains even though a plurality of antennas are combined so as to constitute a diversity antenna system.